VaughnB
Newbie
Hi!
I'm currently in the process of learning the best way to scan black and white negatives, and this same question generally nags me each time I get back into scanning--should I focus slightly in front or behind the negative?
I have a Minolta Scan Elite 5400ii, which has the option of manual focus, moving the negative carrier closer and farther away from the CCD. The whole issue of how to focus on a negative came up for me when I read this article:
http://cool.conservation-us.org/coo...itale/2007-04-vitale-filmgrain_resolution.pdf
If you go to page 3, there's a whole section about the supposedly common technique of focusing on the film grain. Here's the snippet that got me thinking:
"The problems of (1) locating a well-focused region of a small piece of film in a 35 mm film frame (24 x 36 mm), (2) evaluating its degree of focus and then (3) focusing that region of the film, explains why “focusing the grain” has become a common default for determining image sharpness. Focusing on the perceived film grain is a misapplication of imaging
resources. Achieving fine detail with crisp contrast differences should be the goal of the imaging process, be it on a flatbed or drum scanner. Based on the generic information in an MTF Curve, focus is a function maximizing contrast between lights and darks."
I can certainly set the focus on my scanner to resolve the grain, and based on this article, I agree that not focusing on the grain yields an image that appears to be more in focus as a result of the smoothness of not seeing the grain in the image. I am just wondering if there's a best practice that anyone has heard about as far as whether you should focus in front of the negative or past the negative in order to achieve this point of focus that isn't directly on the grain. From everything I've read, it just always about focusing the negative, and I don't have a solid understanding of the physics behind the way either option works when scanning.
Any help or insight would be much appreciated!
I'm currently in the process of learning the best way to scan black and white negatives, and this same question generally nags me each time I get back into scanning--should I focus slightly in front or behind the negative?
I have a Minolta Scan Elite 5400ii, which has the option of manual focus, moving the negative carrier closer and farther away from the CCD. The whole issue of how to focus on a negative came up for me when I read this article:
http://cool.conservation-us.org/coo...itale/2007-04-vitale-filmgrain_resolution.pdf
If you go to page 3, there's a whole section about the supposedly common technique of focusing on the film grain. Here's the snippet that got me thinking:
"The problems of (1) locating a well-focused region of a small piece of film in a 35 mm film frame (24 x 36 mm), (2) evaluating its degree of focus and then (3) focusing that region of the film, explains why “focusing the grain” has become a common default for determining image sharpness. Focusing on the perceived film grain is a misapplication of imaging
resources. Achieving fine detail with crisp contrast differences should be the goal of the imaging process, be it on a flatbed or drum scanner. Based on the generic information in an MTF Curve, focus is a function maximizing contrast between lights and darks."
I can certainly set the focus on my scanner to resolve the grain, and based on this article, I agree that not focusing on the grain yields an image that appears to be more in focus as a result of the smoothness of not seeing the grain in the image. I am just wondering if there's a best practice that anyone has heard about as far as whether you should focus in front of the negative or past the negative in order to achieve this point of focus that isn't directly on the grain. From everything I've read, it just always about focusing the negative, and I don't have a solid understanding of the physics behind the way either option works when scanning.
Any help or insight would be much appreciated!